The massive medieval city wall of Soest (around 1180) is part of the worldwide unique green sandstone ensemble "Altstadt Soest". It is the longest still existing Wallmauer in Germany and from formerly 3.8 km still two thirds are preserved. On this wall and also through the Gräften, in front of which the outer wall used to run, you can take beautiful walks today and look into many an old town garden.
Only Soest and Lucca in Tuscany have such a walkable and tree-covered fortification throughout Europe.